Compressor and control method thereof

Abstract

The present application provides a kind of compressor and its control method, wherein, compressor includes shell and rotating shaft, shell has motor cavity, compression cavity and the partition for separating motor cavity and compression cavity, partition is equipped with the through hole for rotating shaft passing, the rotating shaft is used to be driven by motor assembly in motor cavity and make impeller in compression cavity rotate;Oil blocking sleeve is fixed on rotating shaft;Compressor also has axial force adjusting structure, the position of oil blocking sleeve is adjustable, and when being located in different positions, under the action of axial force adjusting structure, the first axial force that it is subjected to is different;Oil blocking sleeve has at least two positions of the first axial force direction different, the direction of first axial force is parallel to the direction of rotating shaft axis.According to the technical scheme of the present application, the bearing pressure of axial magnetic suspension bearing can be reduced, and the smooth operation of the compressor can be avoided by excessive bearing pressure exceeding the bearing capacity range of axial magnetic suspension bearing.

Description

Technical Field

[0001] This invention belongs to the field of air compression technology, specifically relating to a compressor and its control method. Background Technology

[0002] Compressor impellers typically have a high pressure ratio, which results in a large axial force on the compressor shaft. A thrust disc, working in conjunction with an axial magnetic bearing, is usually installed on the shaft to balance this axial force. Specifically, the axial magnetic bearing applies a counter-thrust to the thrust disc to counteract the axial force exerted by the impeller on the shaft.

[0003] If the axial force exerted by the impeller on the shaft is too large during compressor operation, the axial magnetic bearing will also exert a large reverse thrust on the shaft through the thrust plate to counteract the excessive axial force. If the large axial force exceeds the bearing capacity range of the axial magnetic bearing, it will affect the smooth operation of the compressor. Summary of the Invention

[0004] Therefore, the present invention provides a compressor and its control method. The main technical problem to be solved is: how to reduce the bearing pressure of the axial magnetic levitation bearing and avoid excessive bearing pressure from exceeding the bearing capacity range of the axial magnetic levitation bearing and affecting the stable operation of the compressor.

[0005] To address the aforementioned problems, the present invention provides a compressor comprising a housing and a rotating shaft. The housing has a motor cavity, a compression cavity, and a separator for separating the motor cavity and the compression cavity. The separator has a through hole through which the rotating shaft passes. The rotating shaft is driven by a motor assembly within the motor cavity to rotate an impeller within the compression cavity. An oil-blocking sleeve is fitted onto the rotating shaft and prevents gas from leaking between the compression cavity and the motor cavity through the through hole.

[0006] The compressor also has an axial force adjustment structure, the position of the oil-blocking sleeve is adjustable, and the first axial force it receives is different under the action of the axial force adjustment structure when it is in different positions; wherein, the oil-blocking sleeve has at least two positions with different directions of the first axial force, and the direction of the first axial force is parallel to the axis of the rotating shaft.

[0007] In some embodiments, the axial force adjustment structure includes a shielding structure that remains relatively fixed to the housing; the oil-blocking sleeve has a first side located on the compression chamber side and a second side located on the motor chamber side, with a gap between the first side and the impeller; the oil-blocking sleeve can be adjusted to a first position and a second position with different directions of the first axial force.

[0008] When the oil-blocking sleeve is in the first position, at least a portion of the first side of its first side and the second side is blocked by the blocking structure, so that the pressure at the blocked position on the first side is lower than the pressure in the gap; and when it is in the second position, at least a portion of the second side of its first side and the second side is blocked by the blocking structure, so that the pressure at the blocked position on the second side is lower than the pressure in the motor cavity.

[0009] In some embodiments, the shielding structure includes a groove disposed on the wall of the through hole, and the outer edge of the oil-blocking sleeve extends into the groove; the groove has a first groove wall opposite to the first side surface and a second groove wall opposite to the second side surface; wherein,

[0010] When the oil-blocking sleeve is in the first position, the shielding structure shields at least a portion of the first side through the first groove wall, and a first gap communicating with the motor cavity is formed between the second groove wall and the second side; and / or, when the oil-blocking sleeve is in the second position, the shielding structure shields at least a portion of the second side through the second groove wall, and a second gap communicating with the gap is formed between the first groove wall and the first side.

[0011] In some embodiments, when the oil-blocking sleeve is in the first position, the first groove wall blocks at least a portion of the first side surface through the first comb structure; and / or, when the oil-blocking sleeve is in the second position, the second groove wall blocks at least a portion of the second side surface through the second comb structure.

[0012] In some embodiments, the groove is an annular groove, which has a bottom surface located between the first groove wall and the second groove wall. The bottom surface is sealed to the outer edge of the oil-blocking sleeve to achieve a sealed fit between the oil-blocking sleeve and the through hole.

[0013] In some embodiments, the compressor further includes a position adjustment mechanism; the position adjustment mechanism is used to move the oil blocking sleeve to different positions to adjust the position of the oil blocking sleeve.

[0014] In some embodiments, the position adjustment mechanism includes a first axial magnetic levitation bearing assembly and a thrust plate, the thrust plate being sleeved on the rotating shaft and located between the two axial magnetic levitation bearings of the first axial magnetic levitation bearing assembly;

[0015] The position adjustment mechanism applies force to the thrust plate through the first axial magnetic levitation bearing assembly, causing the thrust plate to drive the oil-blocking sleeve to move to different positions via the rotating shaft.

[0016] In some embodiments, the compressor further includes a detection mechanism and a control mechanism; the detection mechanism is used to detect a second axial force applied by the impeller to the shaft.

[0017] The control mechanism is used to control the position adjustment mechanism to push the oil blocking sleeve to the corresponding position when the second axial force is directed toward the first direction, so that the direction of the first axial force on the oil blocking sleeve is opposite to the first direction.

[0018] In some embodiments, when the oil-blocking sleeve is adjustable to a first position and a second position, if the first direction is from the motor cavity to the compression cavity, the control mechanism controls the position adjustment mechanism to push the oil-blocking sleeve to the second position; if the first direction is from the compression cavity to the motor cavity, the control mechanism controls the position adjustment mechanism to push the oil-blocking sleeve to the first position.

[0019] In some embodiments, the compressor further includes a second axial magnetic bearing assembly for applying a third axial force to the shaft, the third axial force being within the bearing pressure range of the second axial magnetic bearing assembly, the resultant force of the first axial force and the third axial force being a fourth axial force, and the impeller applying a fifth axial force to the shaft, the fourth axial force and the fifth axial force being in opposite directions.

[0020] In some embodiments, the compressor has a primary impeller with a shaft, and the side of the shaft facing away from the motor cavity has a clamping surface for holding a wrench.

[0021] The present invention also provides a method for controlling a compressor, comprising:

[0022] Detect the second axial force exerted by the impeller on the shaft;

[0023] When the second axial force is directed toward the first direction, the position adjustment mechanism is controlled to push the oil-blocking sleeve to the corresponding position, so that the direction of the first axial force on the oil-blocking sleeve is opposite to the first direction.

[0024] In some embodiments, when the oil-blocking sleeve is adjustable to a first position and a second position, if the first direction is from the motor cavity to the compression cavity, the position adjustment mechanism is controlled to push the oil-blocking sleeve to the second position; if the first direction is from the compression cavity to the motor cavity, the position adjustment mechanism is controlled to push the oil-blocking sleeve to the first position.

[0025] The compressor and its control method provided by this invention have the following beneficial effects:

[0026] 1. Since the oil-blocking sleeve is fixed on the rotating shaft, the axial force on the oil-blocking sleeve at different positions will be fed back to the rotating shaft. When the axial force exerted on the rotating shaft by the air pressure in the compression chamber is too large, the position of the oil-blocking sleeve can be adjusted so that the direction of the first axial force on the oil-blocking sleeve is opposite to the axial force exerted on the rotating shaft by the air pressure in the compression chamber, thereby weakening the axial force exerted on the rotating shaft by the air pressure in the compression chamber. This can reduce the bearing pressure of the axial magnetic levitation bearing, so as to avoid the bearing pressure of the axial magnetic levitation bearing exceeding the bearing capacity range and affecting the stable operation of the compressor.

[0027] 2. The detection mechanism, control mechanism and position adjustment mechanism work together to achieve automatic adjustment of the oil blocking sleeve position, making the adjustment of the oil blocking sleeve position more convenient.

[0028] 3. By setting a clamping surface, such as a hexagonal nut contour structure, on the first-stage impeller, the shaft locking surface can be used to lock and disassemble the impeller separately when the locking nut is tightened. This makes assembly and disassembly simpler and more reliable, and eliminates the need to design related clamping and fixing surface features and special fitting tools separately on the other end of the shaft or other parts. Attached Figure Description

[0029] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0030] Figure 1 This is a partial cross-sectional view of the compressor of the present invention;

[0031] Figure 2 This is a schematic diagram of the structure of the first-stage impeller of the compressor of the present invention;

[0032] Figure 3 This is a structural schematic diagram of the first-stage impeller of the compressor of the present invention from another perspective;

[0033] Figure 4 This is a schematic diagram of the structure of the compressor shaft of the present invention.

[0034] The attached figures are labeled as follows:

[0035] 1. Locking nut; 2. First diffuser; 3. First stage impeller; 4. Second diffuser; 5. Support sleeve; 6. First return valve; 7. Second return valve; 8. Impeller; 9. Diffuser; 10. First oil-blocking seal; 11. Oil-blocking sleeve; 12. Second oil-blocking seal; 13. Shaft; 13-1. Pin hole; 14. First groove wall; 15. Bottom surface; 16. Second groove wall; 17. First axial magnetic levitation bearing assembly; 18. Thrust plate; 19. Motor cavity; 20. Compression cavity; 21. First axial magnetic levitation bearing assembly; 100. Separator; 101. Groove; 102. Gap; 103. Through hole; S, First side surface; S2, Second side surface; 3-1. Clamping surface; 3-2. Pin. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0038] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0039] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the structures, proportions, sizes, etc., shown in the accompanying drawings are only for the purpose of illustrative purposes and to facilitate understanding and reading by those skilled in the art, and are not intended to limit the conditions under which the invention can be implemented. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effects and objectives achieved by the invention, should still fall within the scope of the technical content disclosed in the invention. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0040] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0041] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0042] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0043] See also Figure 1 As shown, according to an embodiment of the present invention, a compressor is provided, which includes a housing and a rotating shaft 13. The housing has a motor cavity 19, a compression cavity 20, and a separator 100 for separating the motor cavity 19 and the compression cavity 20. The separator 100 is provided with a through hole 103 for the rotating shaft 13 to pass through. The rotating shaft 13 is driven by a motor assembly in the motor cavity 19 to rotate an impeller 8 in the compression cavity 20, so that the impeller 8 compresses the gas in the compression cavity 20. An oil-blocking sleeve 11 is fixed on the rotating shaft 13 and can prevent gas from leaking between the compression cavity 20 and the motor cavity 19 through the through hole 103.

[0044] The aforementioned compressor also has an axial force adjustment structure. The position of the aforementioned oil-blocking sleeve 11 is adjustable, and the first axial force it experiences is different under the action of the axial force adjustment structure when it is in different positions. Specifically, the oil-blocking sleeve 11 has at least two positions with different directions of the first axial force, and the direction of the first axial force is parallel to the axial direction of the rotating shaft 13.

[0045] In the above example, since the oil blocking sleeve 11 is fixed on the rotating shaft 13, the axial force on the oil blocking sleeve 11 at different positions will be fed back to the rotating shaft 13. When the axial force applied by the impeller 8 to the rotating shaft 13 is too large, the position of the oil blocking sleeve 11 can be adjusted so that the direction of the first axial force on the oil blocking sleeve 11 is opposite to the axial force applied by the impeller 8 to the rotating shaft 13, so as to weaken the axial force applied by the impeller 8 to the rotating shaft 13. This can reduce the bearing pressure of the axial magnetic levitation bearing, so as to avoid the bearing pressure of the axial magnetic levitation bearing exceeding the bearing capacity range and affecting the smooth operation of the compressor.

[0046] It should be noted that, based on the actual operating conditions of the compressor, the axial force data applied by the impeller 8 to the shaft 13 under different operating conditions can be obtained by calculating the pressure data of each operating condition. Combined with the bearing capacity range of the axial magnetic levitation bearing, the axial force adjustment structure can be designed so that the oil blocking sleeve 11 can assist the axial magnetic levitation bearing in balancing the axial force of the shaft 13 under different operating conditions.

[0047] To achieve the function of the aforementioned axial force adjustment structure, such as Figure 1As shown, the aforementioned axial force adjustment structure includes a shielding structure that remains relatively fixed to the housing. The oil-blocking sleeve 11 has a first side surface S located on the side of the compression chamber 20 and a second side surface S2 located on the side of the motor chamber 19. A gap 102 exists between the first side surface S and the impeller 8. The oil-blocking sleeve 11 can be adjusted to a first position and a second position with different directions of the first axial force. When the oil-blocking sleeve 11 is in the first position, at least a portion of the first side surface S is shielded by the shielding structure, making the pressure at the shielded position on the first side surface S lower than the pressure in the gap 102. For example, if the pressure in the gap 102 is P1, the pressure at the shielded position on the first side surface S can be reduced to half of P1 or directly to 0 under the action of the shielding structure, thereby reducing the first force exerted by the air pressure in the aforementioned gap 102 on the oil-blocking sleeve 11. When the oil-blocking sleeve 11 is in the second position, at least a portion of the second side S2 is blocked by the blocking structure, making the pressure at the blocked position on the second side S2 lower than the pressure inside the motor cavity 19. For example, if the pressure inside the motor cavity 19 is P2, the pressure at the blocked position on the second side S2 can be reduced to half of P2 or directly to 0 under the action of the blocking structure. This reduces the second force exerted by the air pressure inside the motor cavity 19 on the oil-blocking sleeve 11.

[0048] In the above example, since the first axial force on the oil-blocking sleeve 11 is the axial resultant force of the first force exerted on the oil-blocking sleeve 11 by the air pressure in the gap 102 and the second force exerted on the oil-blocking sleeve 11 by the air pressure in the motor cavity 19, by reducing the first force on the oil-blocking sleeve 11 in the first position and reducing the second force in the second position, the first axial force on the oil-blocking sleeve 11 in the first position and the second position can be different; and by designing the shielding area of ​​the oil-blocking sleeve 11 in the first position and the second position, the direction of the first axial force on the oil-blocking sleeve 11 in the first position and the second position can be different, thereby realizing the function of the aforementioned axial force adjustment structure.

[0049] In some implementations, such as Figure 1As shown, the aforementioned shielding structure may include a groove 101 provided on the wall of the through hole 103, and the outer edge of the aforementioned oil-blocking sleeve 11 extends into the groove 101. The groove 101 has a first groove wall 14 and a second groove wall 16. The first groove wall 14 is opposite to the aforementioned first side surface S, and the second groove wall 16 is opposite to the aforementioned second side surface S2. When the oil-blocking sleeve 11 is in the first position, the shielding structure can shield at least a portion of the first side surface S through the first groove wall 14, and a first gap communicating with the motor cavity 19 is formed between the second groove wall 16 and the second side surface S2. That is, the shielding structure does not shield the second side surface S2, but only shields at least a portion of the first side surface S. Similarly, when the oil-blocking sleeve 11 is in the second position, the shielding structure can shield at least a part of the second side surface S2 through the second groove wall 16, and a second gap communicating with the aforementioned gap 102 is formed between the first groove wall 14 and the first side surface S. That is, the shielding structure will not shield the first side surface S, but only shield at least a part of the second side surface S2.

[0050] In the above example, when the oil blocking sleeve 11 is in the first position or the second position, the corresponding side (first side S or second side S2) of the oil blocking sleeve 11 is blocked by the corresponding groove wall (first groove wall 14 or second groove wall 16) of the groove 101, which can realize the function of the aforementioned blocking structure. Moreover, the groove 101 has a simple structure and is easy to process.

[0051] In some implementations, such as Figure 1 As shown, when the oil-blocking sleeve 11 is in the first position, the aforementioned first groove wall 14 can block at least a portion of the first side surface S through the first comb structure. The first comb structure can be provided only on the first groove wall 14, only on the first side surface S, or both the first groove wall 14 and the first side surface S can have the first comb structure.

[0052] In the example above, the first comb-tooth structure helps to assist in sealing between the oil-blocking sleeve 11 and the through hole 103.

[0053] like Figure 1 As shown, when the oil-blocking sleeve 11 is in the second position, the second groove wall 16 blocks at least a portion of the second side surface S2 through the second comb structure. The second comb structure can be provided only on the second groove wall 16, only on the second side surface S2, or both the second groove wall 16 and the second side surface S2 may have the second comb structure.

[0054] In the example above, the second comb structure helps to assist in sealing between the oil-blocking sleeve 11 and the through hole 103.

[0055] In some implementations, such as Figure 1As shown, the aforementioned groove 101 can be an annular groove, which has a bottom surface 15 located between the first groove wall 14 and the second groove wall 16. The bottom surface 15 is sealed to the outer edge of the oil-blocking sleeve 11 to achieve a sealed fit between the oil-blocking sleeve 11 and the through hole 103. Preferably, the bottom surface 15 and the outer edge of the oil-blocking sleeve 11 are sealed to each other through a third comb tooth structure. The third comb tooth structure can be provided only on the bottom surface 15, only on the outer edge of the oil-blocking sleeve 11, or both the bottom surface 15 and the outer edge of the oil-blocking sleeve 11 can have the third comb tooth structure.

[0056] In some embodiments, the aforementioned compressor may further include a position adjustment mechanism for moving the oil-blocking sleeve 11 to different positions to adjust the position of the oil-blocking sleeve 11.

[0057] In the above example, the position adjustment mechanism allows for adjustment of the position of the oil-blocking sleeve 11 according to the actual working conditions, so as to balance the axial force on the rotating shaft 13.

[0058] To achieve the functions of the aforementioned position adjustment mechanism, such as Figure 1 The aforementioned position adjustment mechanism may include a first axial magnetic levitation bearing assembly 17 and a thrust plate 18. The thrust plate 18 is fixed on the rotating shaft 13 and is located between the two axial magnetic levitation bearings of the first axial magnetic levitation bearing assembly 17. The position adjustment mechanism applies force to the thrust plate 18 through the first axial magnetic levitation bearing assembly 17, causing the thrust plate 18 to drive the oil-blocking sleeve 11 to different positions via the rotating shaft 13.

[0059] In the above example, the position adjustment mechanism does not directly drive the oil-blocking sleeve 11 to move, because the oil-blocking sleeve 11 is fixed on the rotating shaft 13. The position adjustment mechanism can drive the rotating shaft 13 to move by pushing the thrust plate 18, and then drive the oil-blocking sleeve 11 to different positions through the rotating shaft 13. In this way, the position adjustment mechanism can adjust the position of the oil-blocking sleeve 11.

[0060] In some embodiments, the aforementioned compressor may further include a detection mechanism and a control mechanism. The detection mechanism is used to detect the second axial force applied by the impeller 8 to the shaft 13. The control mechanism is used to control the position adjustment mechanism to move the oil-blocking sleeve 11 to a corresponding position when the second axial force is directed in the first direction, so that the direction of the first axial force on the oil-blocking sleeve 11 is opposite to the first direction.

[0061] It should be noted that the aforementioned detection mechanism can detect the air pressure on both sides of the impeller inside the compression chamber 20, and then calculate the second axial force exerted by the impeller 8 on the rotating shaft 13. The specific structure of the detection mechanism is existing technology and will not be described in detail here.

[0062] In the above example, the detection mechanism, control mechanism and position adjustment mechanism work together to achieve automatic adjustment of the position of the oil blocking sleeve 11, thus making the adjustment of the position of the oil blocking sleeve 11 more convenient.

[0063] In a specific application example, when the oil-blocking sleeve 11 is adjustable to the aforementioned first and second positions, if the first direction is from the motor cavity 19 to the compression cavity 20, the control mechanism controls the position adjustment mechanism to push the oil-blocking sleeve 11 to the second position. If the first direction is from the compression cavity 20 to the motor cavity 19, the control mechanism controls the position adjustment mechanism to push the oil-blocking sleeve 11 to the first position.

[0064] In the above example, when the oil-blocking sleeve 11 is in the first position, the first axial force on the oil-blocking sleeve 11 is from the motor cavity 19 to the compression cavity 20; when the oil-blocking sleeve 11 is in the second position, the first axial force on the oil-blocking sleeve 11 is from the compression cavity 20 to the motor cavity 19. By detecting the direction of the second axial force on the rotating shaft 13 and adjusting the oil-blocking sleeve 11 to the corresponding position so that the first axial force is opposite to the second axial force, the axial force on the rotating shaft 13 can be weakened, thereby reducing the bearing pressure of the axial magnetic levitation bearing and preventing the bearing pressure of the axial magnetic levitation bearing from exceeding the bearing capacity range and affecting the smooth operation of the compressor.

[0065] In some implementations, such as Figure 1 As shown, the aforementioned compressor also includes a second axial magnetic levitation bearing assembly 21, which applies a third axial force to the rotating shaft 13. This third axial force is within the bearing pressure range of the second axial magnetic levitation bearing assembly 21. The resultant force of the first and third axial forces is a fourth axial force. The impeller 8 applies a fifth axial force to the rotating shaft 13. The fourth and fifth axial forces are in opposite directions. This allows the second axial magnetic levitation bearing assembly 21 to operate within its bearing capacity range while simultaneously balancing the axial forces on the rotating shaft 13, thereby reducing stress concentration on the rotating shaft 13 and extending its service life.

[0066] It should be noted that the second axial magnetic bearing assembly 21 and the first axial magnetic bearing assembly 17 mentioned above can be the same axial magnetic bearing assembly, which can save costs.

[0067] In a specific application example, such as Figure 1As shown, the aforementioned separator 100 may include a diffuser 9 located on the compression chamber 20 side, a first oil-blocking seal 10 located on the motor chamber 19 side, and a second oil-blocking seal 12 located between the diffuser 9 and the first oil-blocking seal 10. The diffuser 9, the first oil-blocking seal 10, and the second oil-blocking seal 12 together form the aforementioned groove 101.

[0068] To facilitate understanding, the principle of axial force adjustment of shaft 13 will be explained below.

[0069] In a specific application example, such as Figure 1 As shown, the first side S of the oil-blocking sleeve 11 has an S1 surface opposite to the first groove wall 14 and an S3 surface that is always opposite to the impeller 8. The second side S2 of the oil-blocking sleeve 11 is opposite to the second groove wall 16. The pressure in the aforementioned gap 102 is P1, and the pressure in the motor cavity 19 is P2.

[0070] When the oil-blocking sleeve 11 is in the middle position of the groove 101, the second gap formed between the first side surface S of the oil-blocking sleeve 11 and the first groove wall 14 of the groove 101 communicates with the aforementioned gap 102, and the first gap formed between the second side surface S2 of the oil-blocking sleeve 11 and the second groove wall 16 of the groove 101 communicates with the motor cavity 19. At this time, the pressure on surface S1 is P3 = P1, the pressure on surface S2 is P4 = P2, and the first axial force F0 on the oil-blocking sleeve 11 is F0 = P1*S3 + P1*S1 - P2*S2.

[0071] When the oil-blocking sleeve 11 is in the first position, the S1 surface of the oil-blocking sleeve 11 is pressed tightly against the first groove wall 14 of the groove 101, forming a seal on the S1 surface. The pressure on the S1 surface is P3 = 1 / 2P1, and the pressure on the S2 surface is P4 = P2. At this time, the first axial force F1 on the oil-blocking sleeve 11 is F1 = P1*S3 + 1 / 2P1*S1 - P2*S2. The direction of F1 is towards... Figure 1 The left side of the image is the direction from the motor cavity 19 to the compression cavity 20.

[0072] When the oil-blocking sleeve 11 is in the second position, the S2 surface of the oil-blocking sleeve 11 is pressed tightly against the second groove wall 16 of the groove 101, forming a seal on the S2 surface. The pressure on the S1 surface is P3 = P1, and the pressure on the S2 surface is P4 = 1 / 2P2. At this time, the first axial force F2 on the oil-blocking sleeve 11 is F2 = P1*S3 + P1*S1 - 1 / 2P2*S2. The direction of F2 is towards... Figure 1 The right side of the image is the direction from the compression chamber 20 to the motor chamber 19.

[0073] In summary, it can be seen that the first axial force on the oil-blocking sleeve 11 is different in different positions. Therefore, the axial force on the rotating shaft 13 can be adjusted by adjusting the oil-blocking sleeve 11 to different positions. Specifically, during installation, the oil-blocking sleeve 11 can be adjusted to the corresponding first position, second position, or intermediate position according to the actual axial force required by the rotating shaft 13.

[0074] The compressor of this invention is applicable to magnetic levitation compressors. These compressors utilize an axial magnetic levitation bearing to generate electromagnetic force, which in turn exerts an axial force on the rotating shaft 13, positioning it at a predetermined axial center. For different operating conditions of the compressor, the axial force data on the rotating shaft 13 is obtained by calculating the corresponding pressure data. The direction and magnitude of the current in the axial magnetic levitation bearing vary; a larger current indicates a larger net axial force on the rotating shaft 13. For example, a positive current generates a leftward suction force, while a negative current generates a rightward suction force.

[0075] When the axial resultant force on the entire shaft 13 under the operating condition points in the direction Figure 1 When at the left end, by controlling the instantaneous increase of the current in the first axial magnetic levitation bearing assembly 17, an electromagnetic force is generated to push the rotating shaft 13, causing the oil-blocking sleeve 11 to move to the aforementioned second position. At this time, the first axial force on the oil-blocking sleeve 11 is to the right, which can balance the axial resultant force on the rotating shaft 13 to the left. After the working condition stabilizes, the axial resultant force on the rotating shaft 13 decreases, and the load on the first axial magnetic levitation bearing assembly 17 is smaller. When the axial resultant force on the rotating shaft 13 as a whole is directed towards... Figure 1 At the right end, by controlling the instantaneous increase of the current of the first axial magnetic levitation bearing assembly 17, an electromagnetic force is generated to push the rotating shaft 13, causing the oil blocking sleeve 11 to move to the aforementioned first position. At this time, the first axial force on the oil blocking sleeve 11 is to the left, which can balance the axial resultant force to the right on the rotating shaft 13. After the working condition stabilizes, the axial resultant force on the rotating shaft 13 decreases, and the load on the first axial magnetic levitation bearing assembly is smaller.

[0076] In some embodiments, the compressor of the present invention can perform two-stage compression, such as... Figure 1 As shown, the compressor may further include a first diffuser 2, a second diffuser 4, and a first-stage impeller 3. The aforementioned diffuser 9 is a third diffuser, and the aforementioned impeller 8 is a second-stage impeller. The compressor also includes a support sleeve 5, a first return valve 6, and a second return valve 7.

[0077] In some implementations, such as Figure 2 As shown, the compressor may have a first-stage impeller 3, which has a shaft, and a clamping surface 3-1 for a wrench is provided on the side of the shaft away from the motor cavity 19.

[0078] The clamping surface 3-1 can be a hexagonal nut profile structure, and the axle of the first-stage impeller 3 is sleeved on the rotating shaft 13 and circumferentially fixed to it. Specifically, as follows... Figure 3 and Figure 4 As shown, the impeller mating section of the rotating shaft 13 is provided with a pin hole 13-1. The impeller mating section of the rotating shaft 13 is mated with the shaft of the first-stage impeller 3 by a pin 3-2, wherein the pin 3-2 is inserted into the pin hole 13-1 on the rotating shaft 13. Under the restraining effect of the pin 3-2, the impeller 8 and the rotating shaft 13 cannot rotate circumferentially.

[0079] For compressors with impellers suspended at both ends, two torque wrenches are typically used to simultaneously clamp the locking nuts 1 at both ends during assembly and tightening, thus locking both impellers. Similarly, when disassembling the impellers, torque wrenches are used to apply opposing torque to loosen the locking nuts 1. Often, only one locking nut 1 loosens, while the other remains attached. In this case, a pneumatic wrench is used to apply a strong, instantaneous impact to loosen the detached locking nut 1. This disassembly method is inefficient, and the forceful impact of the pneumatic wrench may affect the quality of the locking nuts 1 and the impeller; repeated disassembly can impact the compressor's reliability. Furthermore, when the locking nuts 1 on both impellers rotate in opposite directions, additional clamping features must be designed on the shaft 13, along with appropriate tooling, for tightening or loosening.

[0080] For compressors with two-stage impellers arranged at one end, when tightening the locking nut 1, it is usually necessary to design a hexagonal nut-like clamping and fixing surface at the other end of the shaft and design a matching tooling, which makes the rotor structure more complex and the processing cost higher.

[0081] In this invention, a clamping surface 3-1, such as a hexagonal nut contour structure, is provided on the impeller. When locking the locking nut 1, the hexagonal nut contour structure on the impeller can be used to clamp and lock the locking nut 1 separately. For a compressor with both impellers suspended at one end, the impeller at the symmetrical secondary end can be locked separately like the locking nut 1. Similarly, when disassembling the impeller, the hexagonal nut contour structure can be used to disassemble the primary and secondary impellers separately. For a compressor with only one impeller suspended at one end, the other end of the shaft 13 does not need a separate hexagonal nut contour structure. During normal operation, the impeller rotates clockwise, and the locking nut 1 rotates right-handed (in the same direction as the impeller's rotation). The locking nut 1 on the symmetrical side rotates left-handed (in the same direction as the symmetrical side impeller's rotation), preventing the locking nuts 1 at both ends from loosening during operation.

[0082] The present invention provides a clamping surface 3-1, such as a hexagonal nut contour structure, on the first-stage impeller 3. This allows for separate locking of the shaft 13 and disassembly of the impeller when the locking nut 1 is tightened. This makes assembly and disassembly simpler and more reliable, and eliminates the need to design related clamping and fixing surface features and special fitting tools separately on the other end or other parts of the shaft 13.

[0083] The present invention also provides a method for controlling a compressor, wherein the compressor is the aforementioned compressor having a detection mechanism and a control mechanism. The method for controlling the compressor includes:

[0084] Step S1: Detect the second axial force applied by the impeller 8 to the shaft 13.

[0085] Step S2: When the second axial force is directed toward the first direction, the control position adjustment mechanism pushes the oil blocking sleeve 11 to the corresponding position so that the direction of the first axial force on the oil blocking sleeve 11 is opposite to the first direction.

[0086] In the above example, by combining steps S1 and S2, the position of the oil-blocking sleeve 11 can be automatically adjusted, making the adjustment of the position of the oil-blocking sleeve 11 more convenient.

[0087] In some embodiments, when the aforementioned oil-blocking sleeve 11 is adjustable to a first position and a second position, if the first direction is from the motor cavity 19 to the compression cavity 20, the position adjustment mechanism is controlled to push the oil-blocking sleeve 11 to the aforementioned second position; if the first direction is from the compression cavity 20 to the motor cavity 19, the position adjustment mechanism is controlled to push the oil-blocking sleeve 11 to the aforementioned first position.

[0088] In the above example, when the oil-blocking sleeve 11 is in the first position, the first axial force on the oil-blocking sleeve 11 is from the motor cavity 19 to the compression cavity 20; when the oil-blocking sleeve 11 is in the second position, the first axial force on the oil-blocking sleeve 11 is from the compression cavity 20 to the motor cavity 19. By detecting the direction of the second axial force on the rotating shaft 13 and adjusting the oil-blocking sleeve 11 to the corresponding position so that the first axial force is opposite to the second axial force, the axial force on the rotating shaft 13 can be weakened, thereby reducing the bearing pressure of the axial magnetic levitation bearing and preventing the bearing pressure of the axial magnetic levitation bearing from exceeding the bearing capacity range and affecting the smooth operation of the compressor.

[0089] It will be readily understood by those skilled in the art that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0090] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A compressor, characterized in that: The device includes a housing, an oil-blocking sleeve (11), and a rotating shaft (13). The housing has a motor cavity (19), a compression cavity (20), and a partition (100) for separating the motor cavity (19) and the compression cavity (20). The partition (100) has a through hole (103) for the rotating shaft (13) to pass through. The rotating shaft (13) is driven by a motor assembly in the motor cavity (19) to rotate an impeller (8) in the compression cavity (20). The oil-blocking sleeve (11) is fitted onto the rotating shaft (13) and can prevent air leakage between the compression cavity (20) and the motor cavity (19) through the through hole (103). The compressor also has an axial force adjustment structure. The position of the oil-blocking sleeve (11) is adjustable, and the first axial force it receives is different under the action of the axial force adjustment structure when it is in different positions. The oil-blocking sleeve (11) has at least two positions with different directions of the first axial force, and the direction of the first axial force is parallel to the axis of the rotating shaft (13). The axial force adjustment structure includes a shielding structure that is relatively fixed to the housing. The oil-blocking sleeve (11) has a first side surface (S) located on the side of the compression chamber (20) and a second side surface (S2) located on the side of the motor chamber (19). There is a gap (102) between the first side surface (S) and the impeller (8). The oil-blocking sleeve (11) can be adjusted to a first position and a second position with different directions of the first axial force. When the oil-blocking sleeve (11) is in the first position, at least a portion of the first side surface (S) of the first side surface (S) and the second side surface (S2) is shielded by the shielding structure, so that the pressure at the shielded position on the first side surface (S) is lower than the pressure in the gap (102). And when the oil-blocking sleeve (11) is in the second position, at least a portion of the second side surface (S2) of the first side surface (S) and the second side surface (S2) is shielded by the shielding structure, so that the pressure at the shielded position on the second side surface (S2) is lower than the pressure in the motor chamber (19).

2. The compressor according to claim 1, characterized in that: The shielding structure includes a groove (101) provided on the wall of the through hole (103), and the outer edge of the oil-blocking sleeve (11) extends into the groove (101); the groove (101) has a first groove wall (14) opposite to the first side surface (S) and a second groove wall (16) opposite to the second side surface (S2); wherein, When the oil-blocking sleeve (11) is in the first position, the shielding structure shields at least a portion of the first side surface (S) through the first groove wall (14), and a first gap communicating with the motor cavity (19) is formed between the second groove wall (16) and the second side surface (S2); and / or, when the oil-blocking sleeve (11) is in the second position, the shielding structure shields at least a portion of the second side surface (S2) through the second groove wall (16), and a second gap communicating with the gap (102) is formed between the first groove wall (14) and the first side surface (S).

3. The compressor according to claim 2, characterized in that: When the oil-blocking sleeve (11) is in the first position, the first groove wall (14) blocks at least a portion of the first side surface (S) through the first comb structure; and / or, when the oil-blocking sleeve (11) is in the second position, the second groove wall (16) blocks at least a portion of the second side surface (S2) through the second comb structure.

4. The compressor according to claim 2, characterized in that: The groove (101) is an annular groove, and the annular groove has a bottom surface (15) located between the first groove wall (14) and the second groove wall (16). The bottom surface (15) is sealed to the outer edge of the oil-blocking sleeve (11) to achieve a sealed fit between the oil-blocking sleeve (11) and the through hole (103).

5. The compressor according to any one of claims 1 to 4, characterized in that: It also includes a position adjustment mechanism; The position adjustment mechanism is used to push the oil blocking sleeve (11) to different positions to adjust the position of the oil blocking sleeve (11).

6. The compressor according to claim 5, characterized in that: The position adjustment mechanism includes a first axial magnetic levitation bearing assembly (17) and a thrust plate (18). The thrust plate (18) is fixed on the rotating shaft (13) and located between the two axial magnetic levitation bearings of the first axial magnetic levitation bearing assembly (17). The position adjustment mechanism applies force to the thrust plate (18) through the first axial magnetic levitation bearing assembly (17), causing the thrust plate (18) to drive the oil blocking sleeve (11) to move to different positions through the rotating shaft (13).

7. The compressor according to claim 5, characterized in that: It also includes testing and control agencies; The detection mechanism is used to detect the second axial force exerted by the impeller (8) on the shaft (13); The control mechanism is used to control the position adjustment mechanism to push the oil blocking sleeve (11) to the corresponding position when the second axial force is directed toward the first direction, so that the direction of the first axial force on the oil blocking sleeve (11) is opposite to the first direction.

8. The compressor according to claim 7, characterized in that: When the oil-blocking sleeve (11) can be adjusted to the first position and the second position, if the first direction is from the motor cavity (19) to the compression cavity (20), the control mechanism controls the position adjustment mechanism to push the oil-blocking sleeve (11) to the second position; if the first direction is from the compression cavity (20) to the motor cavity (19), the control mechanism controls the position adjustment mechanism to push the oil-blocking sleeve (11) to the first position.

9. The compressor according to any one of claims 1 to 4, 6 to 8, characterized in that: The compressor also has a second axial magnetic bearing assembly (21), which is used to apply a third axial force to the rotating shaft (13). The third axial force is within the bearing pressure range of the second axial magnetic bearing assembly (21). The resultant force of the first axial force and the third axial force is a fourth axial force. The impeller (8) applies a fifth axial force to the rotating shaft (13). The fourth axial force and the fifth axial force are in opposite directions.

10. The compressor according to any one of claims 1 to 4, 6 to 8, characterized in that: The compressor has a first-stage impeller (3), the first-stage impeller (3) has a shaft, and the side of the shaft away from the motor cavity (19) is provided with a clamping surface (3-1) for a wrench to hold.

11. A control method for the compressor of claim 7 or 8, characterized in that: include: The second axial force exerted by the impeller (8) on the shaft (13) is detected; When the second axial force is directed toward the first direction, the position adjustment mechanism is controlled to push the oil-blocking sleeve (11) to the corresponding position, so that the direction of the first axial force on the oil-blocking sleeve (11) is opposite to the first direction.

12. The compressor control method according to claim 11, characterized in that: When the oil-blocking sleeve (11) can be adjusted to the first position and the second position, if the first direction is from the motor cavity (19) to the compression cavity (20), the position adjustment mechanism is controlled to push the oil-blocking sleeve (11) to the second position; if the first direction is from the compression cavity (20) to the motor cavity (19), the position adjustment mechanism is controlled to push the oil-blocking sleeve (11) to the first position.

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